The present application relates to an oscillator making it possible to generate an adjustable-frequency electric signal.
The field of the invention is the field of electronic circuits and, in particular, of integrated electronic circuits used in the radiofrequency and microwave frequency fields, for example in communication systems.
In the radiofrequency and microwave frequency fields, the most used method for obtaining an adjustable-frequency oscillator consists of modifying the phase-frequency characteristic of the resonator.
In particular, oscillators can be mentioned which are designed around one or more varactors (or voltage-controlled variable capacitors).
This type of component does not however generally allow a frequency variation greater than one octave. Moreover, if it is desired to fully integrate the oscillator, the technology used during the design of the integrated circuit most often complies with choices which are not optimized, in order to obtain a maximum variation of the value of the capacitance of the varactor. The variable capacitor does not therefore make it possible to obtain a frequency variation over a wide frequency band or it must be located outside of the integrated circuit.
Moreover, the introduction of variable components in the resonator creates losses, which reduces the quality factor of the loaded resonator.